The three Lucys by Hayan Charara & Sara Kahn.

The three Lucys by Hayan Charara, illustrated by Sara Kahn. Lee & Low Books 2016. 

Based on true events, this is the story of pets left behind while the family are away for a weekend, but their home - Beirut - is bombed, thus extending their time away. 

On their return, one of the cats fails to return. The narrator finds comfort in the rebuilding of his city, and in his memories of his cat, Lucy Lucy.

The harmonica by Dawn McMillan

The harmonica by Dawn McMillan, illustrated by Andrew Burdan. Scholastic 2016. 

Carlos finds his late uncle’s harmonica in the attic. Uncle Jack died, presumably in war, before Carlos was born. Carlos feels connected to his uncle through the music of the harmonica.

A gentle story, which emphasises the importance of family memory and connection. 

Thunderwith by Libby Hathorn

Thunderwith by Libby Hathorn. Little, Brown and Company, 1991.

Lara goes to live with her father, whom she can barely remember, after the death of her mother. Lara has to adjust to a different lifestyle, one with a hostile stepmother and little half-siblings. Lara's passage is made easier by the existence of Thunderwith, a dingo-looking dog. When Thunderwith is shot and dies, Lara can feel the presence of her mother closer than before, comforting her. 

Onion tears by Diana Kidd

Onion tears by Diana Kidd, illustrated by Lucy Montgomery. Orchard Books, 1989.
[Different editions have different illustrators]

Nam-Huong is adjusting to life in Australia after escaping from the Vietnam War. Having left behind her whole family, and unsure whether they are alive or not, Nam is unsure how to react to normal life. Eventually Nam's memories erupt and she talks through her memories and emotions with a sympathetic teacher, thus enabling her to move on.